Nearly a year after NASA trumpeted Voyager 1’s departure from the sun’s protective bubble, two mission scientists argue that the spacecraft never left. Many astronomers are doubtful about the assertion, but the debate illustrates that the transition from solar bubble to interstellar space is not clear-cut.

“My tendency is to think we are out in interstellar space, but I’m not completely...

It’s finally official: Voyager 1 has become the first human-made object to enter interstellar space, mission scientists report September 12 in Science. On August 25, 2012, the scientists say, Voyager 1 exited a giant invisible bubble called the heliosphere that is inflated by a torrent of subatomic particles spewing from the sun. Now the probe is surrounded almost exclusively by particles...

Humankind has officially extended its reach to the space between the stars. NASA’s Voyager 1 spacecraft exited the vast bubble of particles that encircles the sun and planets on August 25, 2012, mission scientists report September 12 in Science. At the time, Voyager was about 18.2 billion kilometers from the sun, or nearly 122 times as far from the sun as Earth.

To catch the faint signal of a spacecraft leaving the solar system, you have to listen very carefully. At NASA’s Jet Propulsion Laboratory in Pasadena, Calif., that’s Suzanne Dodd’s job.

Dodd (below) is project manager for NASA’s twin Voyager probes, launched in 1977 to explore Jupiter and Saturn. Voyager 2 did that and more, as the first probe to fly by Uranus, in 1986, and Neptune, in...

The Voyager 1 space probe has merged into a newly discovered zone at the solar system’s edge, and scientists think the craft’s next destination could be interstellar space. Measurements from Voyager’s erratic transition, presented at a meeting in December (SN: 1/12/13, p. 17) and in the June 27 Science, reveal that the probe no longer encounters particles emanating from the sun. But Voyager 1...

On its way out of the solar system, the Voyager 1 spacecraft has encountered a “magnetic highway” of charged particles — a hint that the spacecraft may not have far to go before reaching the brink of interstellar space.

This so-called highway lies where the sun’s magnetic field and the interstellar magnetic field meet. Particles blown outward by the solar wind are speeding in...

NASA’s Voyager 1 spacecraft, launched 35 years ago on September 5, 1977, is bracing for a controlled plunge into interstellar space. Soon the craft will leave the solar system behind, bursting through the windy bubble blown by sun.

The question is: How soon? That boundary may be a bit farther away than expected, a team from the Johns Hopkins University Applied Physics...

There are no signs to announce the edge of the solar system, but when the venerable Voyager 2 spacecraft approached this final frontier last Aug. 31 it was in for quite a shock. So were the scientists who analyzed the data that the craft radioed back to Earth, along with related observations by NASA’s twin Earth-orbiting STEREO spacecraft.

On the interplanetary highway, there are no mile markers and no exit signs. Precious few clues indicate that you're nearing the edge of the solar system. Those clues, however, are revealing that the venerable Voyager 1 spacecraft, launched 26 years ago and now 90 times as far from the sun as Earth is, either has reached or will soon enter a turbulent region near the solar system's final...